One mole (mol) of ethanol (C2H60) has a mass of 46.0684 g. How many moles of ethanol are in an 18.0 g sample?

Need to see how the calculation was done.

the number of moles of ethanol is 18 g sample is 0.390 mol

Explanation:

The computation of the  number of moles of ethanol is 18 g sample is shown below:

= Mass of ethanol sample ÷ molar mass of ethanol

= 18 g ÷ 46.064=84 g

= 0.390 mol

Hence, the number of moles of ethanol is 18 g sample is 0.390 mol

the correct answer is a

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.